1. Выполните действие: a) 4-(9/13); в) 6-1(1/4); г) 4(1/8)+7(5/12).

a) 4 - \frac{9}{13} = \frac{4 \cdot 13}{13} - \frac{9}{13} = \frac{52}{13} - \frac{9}{13} = \frac{52-9}{13} = \frac{43}{13} = 3\frac{4}{13}

Ответ: $$3\frac{4}{13}$$.

в) 6 - 1\frac{1}{4} = 6 - \frac{1 \cdot 4 + 1}{4} = 6 - \frac{5}{4} = \frac{6 \cdot 4}{4} - \frac{5}{4} = \frac{24}{4} - \frac{5}{4} = \frac{24-5}{4} = \frac{19}{4} = 4\frac{3}{4}

Ответ: $$4\frac{3}{4}$$.

г) 4\frac{1}{8} + 7\frac{5}{12} = \frac{4 \cdot 8 + 1}{8} + \frac{7 \cdot 12 + 5}{12} = \frac{33}{8} + \frac{89}{12} = \frac{33 \cdot 3}{8 \cdot 3} + \frac{89 \cdot 2}{12 \cdot 2} = \frac{99}{24} + \frac{178}{24} = \frac{99+178}{24} = \frac{277}{24} = 11\frac{13}{24}

Ответ: $$11\frac{13}{24}$$.